Java multiple classes

http://www.youtube.com/watch?v=XqTg2buXS5o&feature=player_profilepage#t=179s

     tuna tunaObject = new tuna();


Someone care to explain why you need to type "tuna" at the beginning and "tuna()" at the end if you already stated that you're going to use the tuna class at the beggining?
I think I understand the "tunaObject" is(the variable to which you will assign the new class in the main class, right?), but the "new" is still kind of ... I don't understand it either...
:/

Let's take this apart:

tuna tunaObject // we are making a variable called tunaObject that is of type tuna
= new tuna(); // And assigning it to an object made by the tuna constructor function, which must be named tuna.

Why does this not make sense to you?